Plants as a source of green corrosion inhibitors on mild steel in hydrochloric acid: The case of oil extract of leaves of Pistacia lentiscus from Saidia Morocco

peer reviewedThe aim of this work was to characterize the essential oils of Pistacia lentiscus (P.L) from Saidia Morocco and analysis by gas chromatograph interfaced with a mass spectrometer (GC-MS). The Corrosion inhibition effect of organic oil and extract of leaves of Pistacia lentiscus (P.L) of mild steel in 1M HCl solution was carried out using, gravimetric, electrochemical polarization and EIS methods. Experiments are performed by varying concentration of the inhibitor. The inhibition efficiency increases with increased organic oil and extract concentration to attain a maximum value of 96.34 % and 86.59% at 1g/L for oil and extract respectively. The study reveals that oil, was dominated by monoterpene hydrocarbons (44.99%) followed by xygenated monoterpenes (13.66%) and Sesquiterpene hydrocarbons (16.59%). Among them, limonene (18.92%), α-pinene (13.94%), β- caryo phyllene (6.93%) and terpinen-4-ol (5.57%) were identified as major components. The Pistacia lentiscus oil and extract acts a mixed inhibitor and showed a result of the growth in the compactness of the protecting film dressing. The organic oil and extract adsorbs on the mild steel surface according to a Langmuir isotherm adsorption model

Suivi de la qualité bactériologique des eaux de surface du Maroc oriental

L’oued de la Moulouya et ses affluents demeurent les principales ressources en eau pour irriguer les champs agricoles avoisinants de la région de Berkane qui représentent l’activité principale de cette région. L’évaluation de la qualité des eaux de ces ressources s’avère une nécessité pour maintenir leur bon fonctionnement et par la suite assurer un bon rendement des produits agricoles. Pour ce faire, un suivi mensuel de prélèvements des eaux a été réalisé dans l’oued de la Moulouya et son affluent Zegzel-Cherâa durant une année de décembre 2015 à novembre 2016. Ces prélèvements ont fait l’objet d’analyses bactériologiques selon les protocoles décrits par les normes marocaines ISO et les recommandations de l’Organisation mondiale de la santé (OMS). Les analyses bactériologiques ont montré que l’oued de Cherâa est soumis à une forte pollution d’origine humaine et animale, avec une prédominance de la source humaine. En effet, la charge bactérienne (coliformes totaux [CT], coliformes fécaux [CF], Escherichia coli [EC], streptocoques fécaux [SF], etc.) est supérieure aux normes marocaines du Secrétariat d’État auprès du ministère de l’Énergie, des Mines, de l’Eau et de l’Environnement (SEEE, 2007) indiquant ainsi que les eaux sont de mauvaise qualité. L’analyse explicative (ACPn) réalisée sur les variables étudiées a permis de mettre en évidence un gradient de pollution pour l’oued Cherâa et a également fait ressortir l’automne comme la saison la plus chargée en bactéries indicatrices de pollution. L’abondance de ces microorganismes dans les cours d’eau traduit la présence possible de bactéries pathogènes qui pourraient causer des maladies au sein de la population qui utilise ces eaux pour boire et pour l’irrigation. Les eaux de l’oued Cherâa sont impropres à la consommation.The Moulouya wadi and its tributaries are the main water resources for irrigating the neighbouring agricultural fields of the Berkane region, which constitute the main activity of this region. Assessing the water quality of these resources is necessary to maintain their functioning and ensure a good yield for agricultural products. To do this, a monthly water sampling was carried out in the wadi of Moulouya and its tributary Zegzel-Cherâa for one year from December 2015 to November 2016. The samples were subjected to bacteriological analyses according to the protocols described by the Moroccan ISO standards and the recommendations of the World Health Organization (WHO). The bacteriological analyses showed that the wadi of Cherâa is subjected to a strong pollution of human and animal origins, with a predominance of the human source. Indeed, the bacterial load (total coliforms, faecal coliforms, Escherichia coli, faecal streptococci, etc.) is higher than the Moroccan standards of the State Secretariat at the Ministry of Energy, Mines, Water, and Environment (SEEE, 2007) indicating that the waters are of poor quality. The explanatory analysis (PCA) carried out on the studied variables highlighted a pollution gradient for the wadi Cherâa and also showed that the autumn was the season most polluted with higher loads of indicator bacteria. The abundance of these microorganisms in streams reflects the possible presence of pathogenic bacteria that could cause disease in populations that use these waters for drinking and irrigation. The waters of the wadi Cherâa are unfit for consumption

Application of eutrophication indices for assessment of the ecological quality of the Moroccan eastern Mediterranean coast: Ras Kabdana-Saïdia

Eutrophication of littoral seawater is estimated to be one of the main threats to marine biota. Therefore, continuous monitoring is necessary to define areas of potential risk. Our work is an essay to explore the possibility of applying the trophic state index (TRIX) to assess the state of eutrophication along the eastern coast of the Moroccan Mediterranean (Ras Kabdana-Saïdia) in concert with a number of hydro chemical parameters and nutrients descriptors aimed at selection of relevant indicators of marine coastal area ecological quality. Seawater samples were studied monthly during 2018. The following environmental parameters have been considered: temperature, salinity, pH, suspended matter, turbidity, dissolved oxygen, saturation levels, nitrite, nitrate, and orthophosphate. Principal Component Analysis was applied in order to figure out and score the most relevant combination of parameters to discriminate between sites and select representative descriptors (pressure/state) of eutrophication. The following variables are defined as relevant descriptors for classification of the sites: nutrients (N, P) and their molar ratios (N/P), the capacity of the system to produce and sustain organic matter (chlorophyll a), and the trophic state index (TRIX). The results show TRIX values below 4, the eutrophication range indicated that there is no ecological risk. The Ras Kabdana-Saïdia is located in an oligotrophic state

Experimental and Theoretical Investigations of Argania spinosa’s Extracts on the Antioxidant Activity and Mild Steel Corrosion’s Inhibition in 1 M HCl

The aim of the present research is the evaluation of the extraction process effect on the chemical composition, the antioxidant activities, and the mild steel corrosion inhibition ability of Argania spinosa’s extracts (alimentary oil (AO) and hexanic extract of roasted almonds (HERA)). The chemical composition revealed that both extracts have the same major compounds: Palmitic, linoleic, and stearic acids, with their order slightly different. Electrochemical impedance spectroscopy (EIS), weight loss measurements, and polarization curves were used to estimate AO and HERA’s mild steel corrosion’s inhibition capacity. Based on these three methods, AO registered, respectively, 81%, 87%, and 87% inhibition efficiency while HERA registered 78%, 84%, and 82% inhibition efficiency. The antioxidant activity of AO and HERA was examined in parallel with standard antioxidants (gallic acid and quercetin) using two assays: DPPH* scavenging assay and ferric reducing antioxidant power assay (FRAP). AO had less EC50 in both techniques (DPPH*: 3559.08 ± 161.75 μg/mL; FRAP 1288.58 ± 169.21 μg/mL) than HERA (DPPH*: 3621.43 ± 316.05 μg/mL; FRAP 1655.86 ± 240.18 μg/mL). Quantum chemical and molecular dynamic studies were employed to suggest the adsorption mechanism

Experimental and Theoretical Investigations of <i>Argania spinosa</i>’s Extracts on the Antioxidant Activity and Mild Steel Corrosion’s Inhibition in 1 M HCl

The aim of the present research is the evaluation of the extraction process effect on the chemical composition, the antioxidant activities, and the mild steel corrosion inhibition ability of Argania spinosa’s extracts (alimentary oil (AO) and hexanic extract of roasted almonds (HERA)). The chemical composition revealed that both extracts have the same major compounds: Palmitic, linoleic, and stearic acids, with their order slightly different. Electrochemical impedance spectroscopy (EIS), weight loss measurements, and polarization curves were used to estimate AO and HERA’s mild steel corrosion’s inhibition capacity. Based on these three methods, AO registered, respectively, 81%, 87%, and 87% inhibition efficiency while HERA registered 78%, 84%, and 82% inhibition efficiency. The antioxidant activity of AO and HERA was examined in parallel with standard antioxidants (gallic acid and quercetin) using two assays: DPPH* scavenging assay and ferric reducing antioxidant power assay (FRAP). AO had less EC50 in both techniques (DPPH*: 3559.08 ± 161.75 μg/mL; FRAP 1288.58 ± 169.21 μg/mL) than HERA (DPPH*: 3621.43 ± 316.05 μg/mL; FRAP 1655.86 ± 240.18 μg/mL). Quantum chemical and molecular dynamic studies were employed to suggest the adsorption mechanism